On a 32 bit OS, the application can only use 3 Gig of address space (and thus 3 Gig of RAM) directly.
If you run the 32 bit application on a 64 bit OS, then it can address almost 4 Gig of address space.
Thanks for the replies.
I read this on a yahoo list, If you are running 32 bit XP and you’ve 3GB or more of RAM, you should change your boot.ini file to include the 3GB switch so that Photoshop and your machine is able to take advantage of that memory. Otherwise it can only access 2GB.
It sounds like a scary thing to do to me. I read about editing the boot.ini and it said any error can render your computer unbootable.
Any thoughts or advice on this?
Thank you I have decided to leave it as it is.
Marcia
one thing to consider when you have on-board video as opposed to a discreet card (as in many laptops) is that memory from the video card comes from the system memory. so you may not have a full 3 gig available to play with. that can cause start-up problems when setting the switches. there are ways to update boot.ini so you can safely recover should you happen on a setting that’s a problem (keep original lines as an option. show boot menu for say 30 seconds) that way if you choose a bad setting and your system locks up, you simply restart and choose the old (known good) configuration. i wouldn’t recommend it for a bare novice, but it’s not brain surgery and microsoft.com and other ms and non-ms technical sites all have good directions for updating the boot.ini file with the /3gb switch.
Marcia, I can tell you that I tried the 3GB switch a couple of years ago and it made my XP system very unstable. Your mileage may vary.
right. don’t jump in without setting up a way back to your original setup. 🙂
Can PS 32 bit us 4GB RAM?
The real question is can Windows 32 use 4GB RAM?
And the real answer is no.
You CAN change the boot.ini and it can indeed be dangerous. So dangerous that the machine won’t boot so make sure you back everything up before you try it.
Bob
I have enabled the 3GB switch on a XP Pro (32bit) SP3 system with 4GB RAM and CS4 installed. I havent had any problems and I think* Photoshop reports a maximum of 2.6GB available RAM but recommends using up to 1.8GB (71%) which has run without any problems so far. The default setting was around 60%.
[*] Im at work now but can check the exact numbers when I get home.
I used the /3GB switch on and off with xp. My conclusion was that it wasn’t really worth it, because I would always end up with scratch sizes above available RAM anyway. I saw much more performance boost by setting up a dedicated RAID 0 array as scratch disk.
In addition, it only works as advertised if you’re running Photoshop by itself. With heavy multitasking it can actually slow things down because Windows will have to page out the other apps more.
So it might work for some, but it depends on what you do.
